Close-contact multilayer type diffractive optical elements, composed of optical materials, in which two optical components are in close contact and the interface thereof constitutes a diffraction grating, have advantages in that the band of wavelength used can be widened, and also that the alignment between the gratings can be easily carried out.
In these close-contact multilayer type diffractive optical elements, for example, as described in Patent Document 1, of the two optical components sandwiching a diffractive optical surface, it is required that one component exhibit the optical properties of relatively high refractive index and low dispersion while the other component exhibit the optical properties of relatively low refractive index and high dispersion.
With respect to the optical materials with low refractive index and high dispersion as described above, in recent years, research and development of resins with low refractive index and high dispersion that are excellent in terms of light weight and mass production has been advanced. As such resins, ultraviolet curable resins have been attracting attention. For example, it has been disclosed in patent Document 2 that optical components made of a homogeneous resin with low refractive index and high dispersion can be formed by using a bifunctional acrylate and/or methacrylate (hereinafter, simply referred to as a (meth)acrylate) containing a fluorine atom within the molecule, and a bifunctional (meth)acrylate having a fluorene structure.